Revenue Recognition - Summarize Activity of the Net Product Revenue Allowance and Reserve Categories (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning balance	$ 190,827	$ 128,557
Provision related to current period sales	191,325	183,704
Provision related to prior period sales	(854)	(3,209)
Credits/payments made for current period sales	(29,525)	(51,619)
Credits/payments made for prior period sales	(121,126)	(108,651)
Ending balance	230,647	148,782
Trade Allowances
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning balance	36,242	29,261
Provision related to current period sales	29,134	30,640
Credits/payments made for current period sales	(3,582)	(6,872)
Credits/payments made for prior period sales	(7,086)	(29,047)
Ending balance	54,708	23,982
Rebates, Chargebacks and Discounts
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning balance	141,201	90,997
Provision related to current period sales	148,241	133,721
Provision related to prior period sales	(854)	(3,209)
Credits/payments made for current period sales	(16,136)	(33,927)
Credits/payments made for prior period sales	(108,020)	(75,738)
Ending balance	164,432	111,844
Product Returns
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning balance	7,797	4,579
Provision related to current period sales	828	815
Credits/payments made for prior period sales	(402)	(145)
Ending balance	8,223	5,249
Other Incentives
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning balance	5,587	3,720
Provision related to current period sales	13,122	18,528
Credits/payments made for current period sales	(9,807)	(10,820)
Credits/payments made for prior period sales	(5,618)	(3,721)
Ending balance	$ 3,284	$ 7,707